Medical Causes of Depression

There are various medical conditions that increase a person's chances of experiencing a Depressive Episode. These include:

Hypothyroidism: This condition can cause a Depressive Episode, and correcting the thyroid abnormality will help resolve the Depression. This is also true of subclinical hypthyroidism, where the Thyroid Stimulating Hormone (TSH) is elevated even though the thyroid hormone levels appear normal [ref].

Cushing's Disease and other forms of hypercortisolism: High levels of corticosteroids are known to lead to Depression. People with Cushing's Disease or with other conditions where their corticosteroid levels are elevated, including instances where corticosteroids are used as medications to treat another medical condition, have a strong chance of experiencing a Depressive Episode, which may last for several week even after the corticosteroid levels return to normal [ref].

Heart Disease: As many as 30% of individuals who survive a heart attack will suffer from a Depression, and having a Depression worsens a person's chances of recovering from their heart disease [ref, ref] and can also lead to heart disease [ref]. Identifying and treating the Depression in these cases is thus very important because this can improve the outcome of the person's heart disease [ref].

Sleep Apnea: This sleep-related breathing disorder can lead to Depression [ref].

Parkinson's Disease: As many as half of all people with this condition will develop Depression, most likely as a result of the underlying neurological degeneration, and this can then worsen the course of the Parkinson's Disease [ref].

Alzheimer's Disease: Up to half of all people with Alzheimer's Disease will suffer from Depression, which usually occurs during in the early stages of the disease [ref]. When a person develops their first episode of Depression in old age, there should be a suspicion that this could in fact be the early symptoms of Alzheimer's Disease. Having had Major Depressive Disorder also seems to increase the amount of plaques and tangles associated with Alzheimer's Disease [ref].

HIV and AIDS: Depression is common among people infected with HIV or AIDS [ref], and having Depression can worsen the outcome of HIV and AIDS [ref].

Cancer: Many cancer patients will suffer from Depression, especially when they have pain, physical impairments or a poor prognosis of their cancer [ref]. There is some evidence that having Depression can worsen the chances of the person recovering from their cancer and that treating the Depression can help with the cancer treatment [ref]. Pancreatic carcinoma is known for causing Depression in a large proportion of patients, and Depression can be one of the first symptoms of this form of cancer.

Autoimmune disorders: Diseases such as Multiple Sclerosis, Systemic Lupus Erythematosis, and Rheumatoid Arthritis, have all been found to be lead to high rates of Depression.

Seizure disorders (epilepsy): Depression is very common in seizure disorders, and has been found to be associated with some of the treatments for epilepsy as well as with the seizure disorder itself [ref].

Steroids: Long-term use of corticosteroids (such as cortisone or prednisone), anabolic steroids (such as testosterone), and contraceptive pills with high levels of progesterone, can all cause Depression.

Prescription medications: Besides steroids, there are various other prescription medications that can cause Depression, such as Cimetidine, Clonidine, Digitalis, Interferon, Mefloquin, Methyldopa, Phenytoin, Reserpine, and Sulfonamide antibiotics.